cn007b

<?php
class ValueObject
{
    protected $name;
    private function __construct()
    {}
    public static function fromArray(array $args)
    {
        if (!isset($args['name']) || $args['name'] === '') {
            throw new InvalidArgumentException('name cannot be blank');

cn007b

// controller

func SignUp(username string) {
	msg := "ok"
	if err := service.SignUp(username); err != nil {
		msg = err.Error()
	}
	fmt.Printf("[error] SignUp: %s \n", msg)
}

cn007b

// service

func SignUp(username string) error {
	if err := validation(username); err != nil {
		return fmt.Errorf("validation failed, error: %s", err)
	}
	if err := signUpFacebook(username); err != nil {
		return fmt.Errorf("facebook sign up failed, error: %s", err)
	}
	if err := signUpTwitter(username); err != nil {

cn007b

#!/bin/bash

# set -x

f() {
    echo "got: ${1}"
}

for i in $(seq 1 3); do
    r=$(f ${i})

cn007b

func CreateNewUser() {
  name := ...
  email := ...
  // ...
  db.SaveUser(name, email)
  mailer.SendEmail(name, email)
  search.AddUser(name, email)
}

cn007b

type UserInput struct {
	Name  string
	Email string
}

cn007b

package CreateUserVO

import "errors"

type Instance struct {
	// errors contains all validation errors.
	errors map[string]string

	name  string // intentionally non-exported
	email string // intentionally non-exported

cn007b

// New creates new value object instance and performs validation.
func New(data map[string]string) (Instance, error) { // Instance intentionally value, not pointer
	vo := Instance{}
	vo.errors = make(map[string]string)

	vo.initName(data)
	vo.initEmail(data)

	if len(vo.errors) > 0 {
		// if you like panic, you may panic here

cn007b

// initName performs naive name validation (just for sake of example)
// and provides 100% guarantee that vo contains valid name.
func (i *Instance) initName(data map[string]string) {
	name, exists := data["name"]
	if !exists || name == "" {
		i.errors["name"] = "invalid name"
		return
	}

	i.name = name

cn007b

func (i Instance) GetErrors() map[string]string {
	return i.errors
}

func (i Instance) GetName() string {
	return i.name
}

func (i Instance) GetEmail() string {
	return i.email